کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1413940 | 1508877 | 2014 | 8 صفحه PDF | دانلود رایگان |
The preparation of carbide-derived carbon (CDC) monoliths with a hierarchically structure in the nm and μm range is presented. Basis is the manufacturing of porous cellular SiC ceramics based on a biomorphous approach with μm porosity and subsequent conformal conversion to CDC by reactive extraction with chlorine. The SiC ceramics can be sintered at low temperatures and short times (1500 °C, 2 h) compared to classical preparation methods. The SiC ceramics show a macro pore volume (1–10 μm channel size) of 0.56 ml g−1, which corresponds to 1.5 ml g−1 in the resulting CDC. The final carbon material exhibits an additional nano pore volume of 0.525 ml g−1 with a mean slit pore size of 0.86 nm. Mechanical stabilities of the highly porous CDC are excellent (bending strength 2.1 ± 0.2 MPa, corrected Weibull modulus 8.7, characteristic strength 2.2 MPa and Youngs modulus 10.0 ± 0.5 GPa). The reactive extraction of the carbide monoliths shows very high reaction rates, approx. two dimensions faster (95×) compared to non-porous samples. Thus the manufacturing of the structured carbide and CDC can be performed at lower costs.
Journal: Carbon - Volume 70, April 2014, Pages 30–37